Bridging Social Silos for Knowledge Discovery and Sharing

Techniques are provided herein for obtaining network usage information about a plurality of users, analyzing the network usage information to detect a plurality of subjects and determine a set of relationship scores describing the strength of the relationship between users and subjects, and analyzing the sets of relationship scores to detect a plurality of virtual communities formed among the users. The virtual communities are used to detect subjects to recommend to members of the virtual communities, such as topics or content items that other users of the community have found of interest.